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US 2010/0071430 A1Published application
Stretch forming apparatus with supplemental heating and method
AssigneeCyril Bath Company
InventorsLarry Alexander Polen, Thomas Sandy Houston, John E. Owens, JR.
Life of this patent
Estimating the term…
Abstract
A stretch-forming apparatus includes a main frame which carries a die enclosure between jaw assemblies. The die enclosure includes radiant heaters for supplying heat to a workpiece being stretch-formed against the die.
Claims24
A method of stretch-forming, comprising:
- (a) providing an elongated metallic workpiece having a preselected cross-sectional profile;
- (b) providing a die having a working face complementary to the cross-sectional profile, wherein at least the working face comprises a thermally insulated material;
- (c) resistance heating the workpiece to a working temperature by passing electrical current therethrough;
- (d) forming the workpiece against the working face by causing the workpiece and the die to move relative to each other while the workpiece is at the working temperature, thereby causing plastic elongation and bending of the workpiece and shaping the workpiece into a preselected final form;
- and
- (e) at one or more predetermined positions of the workpiece in relation to the die, applying radiant heat to one or more predetermined portions of the workpiece to increase the plastic elongation of the workpiece at the one or more predetermined portions.
3 more elements
The method of claim 6, wherein the step of passing the electrical current to the workpiece comprises the step of passing the electrical current to the workpiece through the jaws .
A stretch-forming apparatus, comprising:
- (a) a die having a working face with a profile adapted to receive and form an elongated metallic workpiece, wherein at least the working face comprises a thermally insulated material;
- (b) a resistance heater for electric resistance heating the workpiece to a working temperature;
- (c) movement elements engaging the workpiece for moving the die and a workpiece relative to each other to elongate and bend workpiece against the working face;
- and
- (d) a radiant heater for applying radiant heat to one or more predetermined portions of the workpiece to increase the plastic elongation of the workpiece at the one or more predetermined portions.
2 more elements
A stretch-forming apparatus, comprising:
- (a) a die having a working face adapted to receive and form an elongated metallic workpiece, wherein at least the working face comprises a thermally insulated material;
- (b) a heater for electric resistance heating the workpiece to a working temperature;
- (c) an enclosure for surrounding the die and a first portion of the elongated workpiece during a forming operation, and for permitting a second portion of the workpiece to protrude therefrom;
- (d) opposed swing arms to which opposing ends of the workpiece are mounted for moving the die and a workpiece relative to each other so as to cause elongation and bending of the workpiece against the working face;
- (e) a radiant heater located to apply radiant heat from a position wherein the heat is applied to a side of the workpiece opposite a working face-engaging side of the workpiece;
- (f) a radiant heater located to apply radiant heat to a side of the workpiece generally perpendicular to a working face-engaging side of the workpiece;
- (g) temperature sensors selected from the group consisting of infrared temperature sensors and thermocouple temperature sensors communicating with a temperature control circuit for determining any variance between an actual and optimum workpiece temperature;
- and
- (h) a servo-feedback loop circuit for applying radiant heat to the workpiece wherein the optimum temperature of the workpiece, the actual temperature of the workpiece and the distance of the workpiece from the radiant heater is correlated and sufficient heat is supplied to the workpiece from the radiant heater to maintain the temperature of the workpiece at the optimum temperature without regard to the distance between the workpiece and the radiant heater.
6 more elements
Dependencies are inferred from the claim text.